dmarek-flex

> * On the modal plane (let's assume it to be xy-plane), compute **J** at every grid point through **J** = Curl **H**. Next we integrate **J**z over the entire...

> > So do you mean an option to create path integrals given P1(x1,y1,z1) and P2(x2,y2,z2) and just ensure that that it is axis aligned with a validator? If so...

> It'll be very helpful to also visualize voltage/current integration path in the plot. Just adding some tests, but path integrals can be plotted now. 

@weiliangjin2021 I am ready to merge this as soon as you confirm. Tests are passing after rebase and my testing notebook is giving good results. I just changed the CHANGELOG...

Maybe lets start with feedback from @QimingFlex and @weiliangjin2021 before we get @tylerflex to review.

> First pass, all look quite good! Any notebook examples? Forthcoming ... :smile:

@weiliangjin2021 @QimingFlex I have been considering modifying lumped elements so that they are a similar composition as `Structure`. Meaning that they are composed of a geometry with some additional details...

> One more question about _admittance_transfer_function_scaling: could we suggest a default box or handle this internally instead of asking users to define one? Users do not need to call this...

> Yeah, I mean the latter. I'm curious about how the box size would affect the final results. We can determine the optimal size internally in the future, so users...

> Since we had `LumpedResistor` already, I wonder if we shall have `LumpedCapacitor` and `LumpedInductor`, even though they are just special cases of RLCNetwork? The only reason I kept `LumpedResistor`...